No abstract

No abstract

a Eight aquatic biota species were collected from an e-waste dismantling area in East China to investigate bioconcentration and trophic transfer of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-pdioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The mean concentrations of PCBs varied widely from 6.01 Â 10 4 to 2.27 Â 10 6 pg per g dry weight (dw). The P 25 PCB concentrations in eels were significantly higher than those in other species. The levels of PCDD/Fs changed from 8.13 pg per g dw in toads to 617 pg per g dw in stone snails. World Health Organization-toxic equivalents (WHO 2005 -TEQs) ranged from 2.57 to 2352 pg WHO-TEQ per g dw with a geometric mean value of 64.7 pg WHO-TEQ per g dw, which greatly exceeded the maximum levels of 4 pg per g ww set by the European Commission. The log-transferred bioconcentration factors (BCFs) of 25 PCB congeners ranged from 1.0 to 6.6, with the highest value for CB-205 in crucian carp and the lowest value for CB-11 in frog. A parabolic correlation was observed between log BCF and log K ow (R 2 ¼ 0.53, p < 0.001), where the maximum value occurred at a log K ow of approximately 7. A similar correlation was also found in the plot of log BCF against the number of chlorine atoms of PCBs (R 2 ¼ 0.57, p < 0.001), indicating that mediumhalogenated congeners of PCBs are more easily accumulated by aquatic biota species. There were no significant correlations between the log-transferred concentrations and trophic levels of aquatic species, suggesting that trophic magnification for PCBs and PCDD/Fs was not observed in this study. Environmental impactE-waste dismantling regions have been the subject of great concern in recent years due to the serious environmental contamination associated with e-waste dismantling activities. As a notorious e-waste recycling area in East China, Taizhou has been a hot spot for persistent organic pollutant (POP) research. The present study was conducted to investigate the bioconcentration and trophic transfer tendencies of PCBs and PCDD/Fs in various aquatic biota species in this ewaste area. The high concentrations of POPs in these species reected the lasting impact of e-waste recycling activities on the local environment over more than three decades. Bioconcentration of PCBs was ubiquitously observed in all the species, and signicant parabolic relationships were found between log BCFs and the number of chlorine atoms of PCB congeners as well as their log K ow s. The present results provided important information about the bioaccumulation tendency of POPs in aquatic biota species.